1. Field of the Invention
The present invention relates to, particularly, a charge coupled device (CCD) type solid-state imaging device, a method of producing the same, and a camera including the same.
2. Description of the Related Art
There is known, as a digital still camera imaging device, a CCD solid-state imaging device has been used well, mostly, it is an interline transfer type (so-called as an “IT type”) CCD. Among them, there are a field integration, a frame integration and a progressive scan.
In the field integration or the frame integration, by dividing the whole pixel information into two times or more and reading out it, there is a merit, for example, that a restriction of a vertical transfer unit (vertical CCD) due to a dynamic range can be avoided. However, due to a read out operation divided into a plurality of times, there is a demerit, for example, of an outflow of a signal charge caused by heat and a difference of a dark current between fields.
In the progressive scan, since the whole pixels can be read out simultaneously, there is a merit, for example, that an accurate optical shatter (mostly, a mechanical shatter) is unnecessary. However, a transfer electrode is configured by a three- or more layers-stacked poly silicon electrode, so that a processing thereof is complicated and a step thereof is increased. Further, an unevenness in the vertical transfer unit becomes obviously, so an eclipse of incident light (namely, light to be incidence to a light receiving portion is blocked off by a shield film) easily occurs due to such unevenness. Therefore, a sensitivity shading and a sensitivity deterioration at a lens opening side may be easily caused.
As the solid-state imaging device for the progressive scan, Japanese Patent No. 2,878,546 discloses a solid-state imaging device in which a transfer electrode with a single layer electrode structure is used and a driving pulse is supplied from a metal interconnection which is an upper layer of the transfer electrode to a separated transfer electrode in the transfer electrode.